SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5004694b66ba753bfc635d8db7635cac4c47ce6afcb1773b274ac532ac9d8f12' 
  AND token = 'bXNTO5HLzjO+hNexOmpnlkadX3urZVittNVeC2og4yA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}